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examples: update hello world example
Our helloworld example thatw e reference from the manual has been a bit complicated to serve a first contact with gstreamer. Since we have and promote playbin2 as a playback api use it here. Based on work from Mathias Hasselmann <mathias.hasselmann@gmx.de> Fixes #424143
This commit is contained in:
Stefan Kost
parent
0e6aa69366
commit
eb05020f58
1 changed files with 58 additions and 93 deletions
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@ -1,115 +1,80 @@
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#include <stdlib.h>
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#include <gst/gst.h>
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static void
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event_loop (GstElement * pipe)
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static gboolean
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bus_call (GstBus * bus, GstMessage * msg, gpointer data)
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{
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GstBus *bus;
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GstMessage *message = NULL;
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gboolean running = TRUE;
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GMainLoop *loop = (GMainLoop *) data;
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bus = gst_element_get_bus (GST_ELEMENT (pipe));
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while (running) {
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message = gst_bus_poll (bus, GST_MESSAGE_ANY, -1);
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g_assert (message != NULL);
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switch (message->type) {
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case GST_MESSAGE_EOS:
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running = FALSE;
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break;
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case GST_MESSAGE_WARNING:{
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GError *gerror;
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gchar *debug;
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gst_message_parse_warning (message, &gerror, &debug);
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gst_object_default_error (GST_MESSAGE_SRC (message), gerror, debug);
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g_error_free (gerror);
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g_free (debug);
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break;
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}
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case GST_MESSAGE_ERROR:{
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GError *gerror;
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gchar *debug;
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gst_message_parse_error (message, &gerror, &debug);
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gst_object_default_error (GST_MESSAGE_SRC (message), gerror, debug);
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g_error_free (gerror);
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g_free (debug);
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running = FALSE;
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break;
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}
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default:
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break;
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switch (GST_MESSAGE_TYPE (msg)) {
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case GST_MESSAGE_EOS:{
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g_print ("End-of-stream\n");
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g_main_loop_quit (loop);
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break;
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}
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gst_message_unref (message);
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case GST_MESSAGE_ERROR:{
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gchar *debug;
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GError *err;
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gst_message_parse_error (msg, &err, &debug);
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g_free (debug);
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g_print ("Error: %s\n", err->message);
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g_error_free (err);
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g_main_loop_quit (loop);
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break;
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}
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default:
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break;
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}
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gst_object_unref (bus);
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return TRUE;
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}
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int
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main (int argc, char *argv[])
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gint
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main (gint argc, gchar * argv[])
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{
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GstElement *bin, *filesrc, *decoder, *audiosink;
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GstElement *conv, *resample;
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GstElement *playbin;
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GMainLoop *loop;
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GstBus *bus;
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gchar *uri;
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gst_init (&argc, &argv);
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if (argc != 2) {
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g_print ("usage: %s <mp3 file>\n", argv[0]);
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exit (-1);
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if (argc < 2) {
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g_print ("usage: %s <media file or uri>\n", argv[0]);
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return 1;
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}
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/* create a new bin to hold the elements */
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bin = gst_pipeline_new ("pipeline");
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g_assert (bin);
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/* create a disk reader */
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filesrc = gst_element_factory_make ("filesrc", "disk_source");
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g_assert (filesrc);
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g_object_set (G_OBJECT (filesrc), "location", argv[1], NULL);
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/* now it's time to get the decoder */
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decoder = gst_element_factory_make ("mad", "decode");
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if (!decoder) {
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g_print ("could not find plugin \"mad\"");
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return -1;
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playbin = gst_element_factory_make ("playbin2", NULL);
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if (!playbin) {
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g_print ("'playbin2' gstreamer plugin missing\n");
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return 1;
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}
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/* also, we need to add some converters to make sure the audio stream
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* from the decoder is converted into a format the audio sink can
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* understand (if necessary) */
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conv = gst_element_factory_make ("audioconvert", "audioconvert");
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if (!conv) {
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g_print ("could not create \"audioconvert\" element!");
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return -1;
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}
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resample = gst_element_factory_make ("audioresample", "audioresample");
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if (!resample) {
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g_print ("could not create \"audioresample\" element!");
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return -1;
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}
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/* take the commandline argument and ensure that it is a uri */
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if (gst_uri_is_valid (argv[1]))
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uri = g_strdup (argv[1]);
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else
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uri = gst_filename_to_uri (argv[1], NULL);
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g_object_set (playbin, "uri", uri, NULL);
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g_free (uri);
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/* and an audio sink */
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audiosink = gst_element_factory_make ("alsasink", "play_audio");
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g_assert (audiosink);
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/* create and event loop and feed gstreamer bus mesages to it */
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loop = g_main_loop_new (NULL, FALSE);
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/* add objects to the main pipeline */
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gst_bin_add_many (GST_BIN (bin), filesrc, decoder, conv,
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resample, audiosink, NULL);
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bus = gst_element_get_bus (playbin);
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gst_bus_add_watch (bus, bus_call, loop);
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g_object_unref (bus);
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/* link the elements */
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gst_element_link_many (filesrc, decoder, conv, resample, audiosink, NULL);
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/* start play back and listed to events */
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gst_element_set_state (playbin, GST_STATE_PLAYING);
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g_main_loop_run (loop);
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/* start playing */
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gst_element_set_state (bin, GST_STATE_PLAYING);
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/* cleanup */
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gst_element_set_state (playbin, GST_STATE_NULL);
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g_object_unref (playbin);
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g_object_unref (loop);
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/* Run event loop listening for bus messages until EOS or ERROR */
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event_loop (bin);
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/* stop the bin */
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gst_element_set_state (bin, GST_STATE_NULL);
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exit (0);
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return 0;
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}
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